1. Field of the Invention
The present invention relates generally to image recording apparatuses and, more particularly, to an image recording apparatus in which even if position of an image of a microfilm or the like to be projected shifts vertically and horizontally from a normal position of the image to be projected upon copying operation, the image can be recorded in the center of copy paper.
2. Description of the Related Art
A conventional microfilm reader/printer has a screen projection mechanism and a printing mechanism such as of an electrophotographic system and is capable of printing on copy paper a microfilm image projected on a screen. In the conventional microfilm reader/printer, however, a position of an image projected on the screen need be adjusted to a predetermined position while moving the microfilm vertically and horizontally so that the image may not be shifted to one side of the copy paper, or part of the paper may not be cut out in printing. In order to facilitate this adjustment, as shown in FIG. 1A, marks (guides) M indicating corners of an outline of an image are provided on a screen S so that the outline of image I to be projected fits in the guides. This fitting enables an image IP to be printed in the center of copy paper P as shown in FIG. 1B. FIGS. 1C-1F show a state that the image is printed with its position deviated from the normal position set by the guides.
In a reader/printer having an automatic retrieval function, however, a position of blip marks for retrieval provided on the microfilm and a position of an image are not definite, and there is a deviation for each frame. Thus, it has been required to adjust the positions thereof for each image when reading the blip marks to stop the film.
For recording an image on the microfilm, there are two modes: a comic mode in which an image is recorded in an erect state as shown in FIG. 2A and a cinematic mode in which an image is recorded rotating 90.degree. as shown in FIG. 2B. When these two kinds of films are projected on the screen, the image should always be made in the erect state, so that the image recorded in the cinematic mode is rotated 90.degree. by a prism to be projected. Further, when the image on the film is recorded with an inclination as shown in FIG. 2C, it is also possible to correct the inclination by employing a prism. However, when a projected image is rotated by employing a prism or the like, the image is deviated vertically and horizontally due to a slight deviation of an optical axis which results from difficulties in strictly matching an optical axis of a projection lens and that of a prism for rotating the image (see FIGS. 1D and 1F). Accordingly, the adjustment of image position is also required.
As a countermeasure to the foregoing problems, it has been considered that the deviation of the position of the image to be projected is automatically corrected. Such apparatuses and methods have been proposed as follows: an apparatus and a method for controlling a timing at which copy paper is fed so as to correct a deviation X (see FIG. 1C) in the direction of copy paper feeding (Japanese Patent Laying-Open No. 63-316071), and an apparatus and a method for controlling a timing at which copy paper is fed so as to correct deviation X in the direction of copy paper feeding and moving a projection lens so as to correct a deviation Y (see FIG. 1E) perpendicular to deviation X (Japanese Patent Laying-Open No. 61-275774).
In the above-described correction in image position, according to the former method, the correction in image position is available in the copy paper feeding direction but not in the direction perpendicular to the copy paper feeding direction. According to the latter method, since a shift of the projection lens varies depending on a magnification set in the projection lens, the shift need be controlled depending on a detected magnification of the projection lens. Since the shift is very small, a precise control mechanism is required. When the directions of longer sides and shorter sides of the image on the microfilm are deviated by 90.degree. from those of longer and shorter sides of copy paper, the image need be rotated by 90.degree. and hence requires employment of the prism for image rotation; however, when the image is rotated by employing the image rotating prism, a projected image deviates vertically and horizontally even if the optical axis of the projection lens slightly deviates from that of the image rotating prism. Therefore, the similar positional correction is necessary in image rotation according to the latter method.